A bead, a marble and a sticker costs $9.60 altogether.
The bead costs $2.20 less than the marble.
The sticker costs $2.50 more than the marble.
How much do 2 stickers cost?
Choose the cheapest item to be 1 u.
The bead costs $2.20 less than the marble.
The cheapest item is the bead.

Cost of the bead = 1 u
Cost of the marble = 1 u + 2.20
Cost of the sticker = 1 u + 2.20 + 2.50 = 1 u + 4.70

Total cost of the bead, the marble and the sticker
= 1 u + 1 u + 2.20 + 1 u + 4.70
= 1 u + 1 u + 1 u + 2.20 + 4.70
= 3 u + 6.9

3 u + 6.90 = 9.60
3 u = 9.60 - 6.90
3 u = 2.70

1 u = 2.70 ÷ 3 = 0.90

Cost of 2 stickers
= 2 x (1 u + 4.70)
= 2 x (0.90 + 4.70)
= 2 x 5.60
= $11.20

Answer(s): $11.20